Fortunately, the Web is full of awesome little tools that can help you alter PDF files without breaking a sweat. We won’t be covering any of the common PDF tasks, like creating, editing, or printing. Rather, let’s look at lesser known PDF tasks that may come in handy for you.

Are you diligent with your PC security habits? It’s a known truth that viruses and malware can hide inside common file formats such as EXE and ZIP, but many people overlook the fact that PDFs can also be malicious. All it takes is for you to open an infected PDF with an unsecure reader. Sounds annoying, doesn’t it?

That’s where Jotti shines. Upload your file to the website and it’ll scan through the file with 20+ different malware scanners, looking for any potential threats hiding within. The process is simple enough that it only takes a few seconds, making it fast and convenient to use for every PDF you ever encounter.

With Online OCR, you simply upload the file (5 MB max size), select the language of the file, and select an output format (TXT, DOCX, or XLSX). The result is a file that’s stripped of most extraneous details, leaving nothing but text.

Without an account, only the first page of the PDF will be scanned. If you register a free account, you get a few more features: multi-page text extractions, extra output formats, extra recognition languages, and more. By default over 40 languages are supported, including Chinese, Japanese, and Korean.

Have you ever had two versions of the same file and wondered what exactly changed between the two? Inspired by the DIFF utility on Unix systems, Diff Now is a web tool that lets you upload two files and compare the differences between them on a line-by-line basis. Differences are categorized as Added, Deleted, and Changed text.

In addition to PDF files, the tool also supports Microsoft documents, source code for dozens of languages, and even some archive formats.

It’s a primitive tool with few options, but it definitely has its uses. You can tell it to save the page in Portrait or Landscape mode, load or ignore images on the page, include or ignore the page’s background, run or ignore JavaScript on the page before converting, and even convert everything to grayscale in case you want to print sans color.

Unfortunately, this tool may be blocked on some networks for its ability to act as a web proxy and avoid certain web filters. (If a certain site is blocked, HTML to PDF could be used to download the page and see what’s on it.)

If you need to quickly limit access to a PDF, PDF Protect makes it easy to encrypt files with a password. What’s great about this tool is that the protection isn’t limited to simple password-protection; you can set varying permission levels to limit what users can do with the file.

Can users insert, delete, or rotate pages? Should users be able to copy or edit text and images in the file? Do you want to limit printing quality? Should the file’s metadata be encrypted? It only takes a few seconds to set up these options. PDF protection has never been this easy.

PDF Unlock claims to “remove passwords and restrictions from secured PDF files,” though that may be a bit misleading depending on what you want. If you have a password-protected or otherwise restricted PDF file, PDF Unlock will remove those passwords and restrictions from the file but you’ll need the proper passwords to do it.

If you’re looking for a tool that will blindly strip away restrictions without needing the passwords at all, this is NOT the tool you want. In other words, it will revert a protected PDF into an unprotected PDF as long as you have the clearance to do so. Don’t get me wrong, though: this is still a nifty tool to know and it removes the nuisance of repeatedly keying in a password.

This last tool is one that will save you a lot of hard drive space over time. PDF Compress takes an uploaded PDF, performs a number of optimizations on it, then offers the compressed version back to you for free download.

If you’re wondering about its effectiveness, just know that it reduced one of the PDF ebooks in my library from 1.5 MB to 1.0 MB for a savings of 33%. The tool will save more space on image-heavy PDFs than text-heavy PDFs, though it will save you space either way.

Did you find these helpful? How often do you tinker around with PDFs? Will you be using these online tools in the future? If you know of any others that are similar, please share them with us in the comments below!

I rely on FoxIt Reader for most tasks, including editing, forms, printing to PDF, etc. I also must have PDFBinder to "bind" several files together into one. If all you want to do is Save as PDF (a/k/a Print to PDF) then CutePDF is a must. All 3 of these are free.

The easiest way that I've found to turn a web page into a PDF is to use Firefox's 'Print Edit' addon to trim the fat off of a page, then 'print' it to PDFCreator. You can get both Firefox and PDFCreator at ninite.com. (...as well as a *lot* of other software. Check it out!)

Or, God forbid, you just actually buy a copy of Acrobat. It can do everything listed above in MUCH higher quality because it can handle real Postscript. Further, you don't run the risk of snooping due to uploading potentially sensitive PDF files to unknown servers run by unknown people. If you need to protect your PDF file, sending it to a random site seems like a bad idea.

Acrobat simply isn't worth the price for people who don't need all the bells and whistles. Better that people buy a simpler low-cost/free app that does only what they need rather than pirate a premium one.

I often use PDF-XChange Viewer (free, Tracker Software) to type and draw on PDFs (think of otherwise non-interactive forms.) If I don't want the next user to be able to change my additions, I print the PDF to PDF (using Bullzip) and send the copy.

I love, love, love FoxIt Phantom Business. I work in the legal field and we are heavy PDF users, editors, and creators. Best Acrobat replacement I've found to date and runs about $80-90 on the overstock or buy type websites. Most folks would be fine with the standard version but if you need to Bate stamp, redact, or create secure forms/docs the business version is what you need.